Part-Time Full-Stack Engineer for AI-Built Web App

Part-Time Full-Stack Engineer — Growing Web App | Long-Term We are looking for an experienced Full-Stack Software Engineer to take ongoing technical ownership of a live and growing web application. The application is already built and in production with active users. Our development process is heavily AI-assisted, including Claude and a dedicated AI engineering agent that helps monitor, troubleshoot, and work on the application. We are looking for a human engineer who can work alongside our existing AI development workflow and serve as the technical owner and escalation point as the product and customer base grow. This is not a build-from-scratch project. We're looking for a long-term engineer who can learn the existing application, maintain its reliability, solve more complex technical problems, implement improvements, and make sure the technology continues to scale appropriately. Current infrastructure/tools include: Supabase Railway Claude / AI-assisted development Dedicated AI engineering agent Whop and other third-party integrations/tools Responsibilities Maintain and monitor the production application Diagnose and resolve bugs and technical issues Handle escalated technical issues reported by customers Investigate issues the AI engineering agent cannot reliably resolve Review and validate AI-generated code and changes when appropriate Implement new features and improvements as requested Work with Supabase, Railway, APIs, databases, authentication, and third-party integrations Monitor application performance and reliability as our user base grows Identify potential problems before they become customer-facing issues Review architecture and recommend improvements when necessary Maintain security, data integrity, backups, and production stability Help improve monitoring, logging, testing, and deployment processes Identify and address technical debt Communicate technical issues and recommendations clearly to a non-technical founder Who We're Looking For You should have: Strong full-stack web development experience Experience maintaining live production applications with real users Strong experience with databases, APIs, authentication, integrations, and deployments Experience with Supabase Experience deploying or maintaining applications on Railway or similar cloud platforms Strong debugging and troubleshooting skills Experience with AI-assisted development tools such as Claude, Cursor, GitHub Copilot, etc. Ability to independently review and understand an existing codebase Ability to evaluate AI-generated code rather than simply accepting its output Understanding of application security, performance, monitoring, and scalability Strong written and spoken English A proactive, ownership-oriented working style Experience with SaaS, membership platforms, customer-facing applications, or startup environments is a plus. Hours & Compensation 5–10 hours per week to start $30–$40 USD/hour Long-term contract Most weeks may be closer to 5 hours, with additional hours available when we're implementing new features, making improvements, or resolving technical issues. We are especially interested in candidates in Latin America because of U.S. time-zone overlap, but exceptional candidates from other regions are welcome to apply. As the application and user base grow, there is potential for the role and number of hours to grow as well.